The technical field generally relates to internal combustion engine technology. More particularly but not exclusively, the present application relates to an exhaust gas aftertreatment process and device for an internal combustion engine equipped with a selective catalytic reduction (SCR) catalyst. Current SCR catalyst and doser configurations have various drawbacks. Variability in current dosing systems can adversely affect SCR catalyst performance. Dosing more reductant than the desired amount, or the amount that can be consumed in the reaction inside the SCR catalyst, wastes reductant and may cause ammonia slip. Dosing less reductant than the desired amount results in lower NOx reduction and an increase in NOx emissions. Presently available injectors are not readily diagnosed to determine if an off-nominal amount of reductant is being injected. Therefore, further technological developments are desirable in this area.